Medical instruments are known which include a handpiece and a medical ultrasonic blade assembly. The handpiece contains an ultrasound transducer. The ultrasonic blade of the assembly makes physical contact with, and is connected to, the handpiece of the assembly only by a threaded connection (internal threads on the blade and external threads on the handpiece) proximate a vibration antinode. This requires multiple turns to attach the blade, requires a torque-limiting device to correctly attach the blade, and is prone to threads being stripped or broken. Quick connections are known which had the blade contact the handpiece at a vibration antinode but provided the force to hold the two members together at a vibration node. This did not work reliably over a wide range of inputs and was not implemented.
Still, scientists and engineers continue to seek improved handpiece and medical ultrasonic blade assemblies and improved medical-instrument connection assemblies.